I finally got some serious miles/hrs racked up on my new (04) Foreman last weekend. It is nearly due for the oil change and valve adjustment. I've looked at a few sites that do the walkthrough on the valves and I have a couple of questions. Is the clearance for both valves .006? Do you need to insert a feeler gage for both valves at the same time, or just one at a time? Second, I don't see the semi-round index "notch" in the flywheel plug hole. It appears to be perfectly round. Any help appreciated.

 

Hey Prong, good to hear your getting some miles on your machine. When I did the valves on my 350 es fourtrax I did the both of them at the same time which was when they are both closed on the compression stroke.There also should be some type of mark on your flywheel for proper alignment.The next best thing would to pick up a manual for it,always a good accessory for your bike.

Framer

 

Theres a round cap , with a metric hex, i believe 10mm or so, that unscrews, then youll be able to see the mark. Make sure youre at the compression stroke. it helps to pull the spark plug out, to make it easier to hit the mark. Wiggle the rocker arms, and both should be loose, if not, spin the crank another 360 degrees.
You can do them, one at a time, or both. they are both done at the same timing mark. and the clearance is .006".

 

I've found the plug to remove to see the flywheel. The problem is that I can't see the witness mark on the hole that you line up the hashmark with the T. I can see the "T" on the flywheel just fine.

 

As long as the "t" is in the "window" on the compression stroke, you are good to go. A couple of degrees off is not going to change the valve adjustment. A "tight" 0.006" runs a lot quieter than a loose 0.006" - you should be able to snuggly re-insert the feeler gage.

 

Thanks to everyone for the help.

 

How to find the correct stroke, that is compression? Remove the tappet covers and turn the engine over the right way (same way it spins when it runs). Watch your intake valve open, and then close. The next T is compression stroke, where you want to take your lash readings.

 

how many is serious miles. if your valves dont click or make any nioise that u can hear dont mess with them. my buddy chuck has almost 5000 miles on his foreman 450 and he never touched his valves sence the day he bought it

 

Actually the scenario for the valve adjustment is reverse of "noisy" valves - rarely does normal operation cause the valve clearance to OPEN up making the valves "noisy". "noisy" valves are usually attributed to camshaft/rocker arm (lifter) wear or someone adjusting the valves to "loose" to begin with - or most commonly mistaken on the overhead valve models with actually being cam chain "slap" from an overstretched cam chain.

The 4 stroke ATV's are BAD about the valve face wearing (most noticable on the intake) and CLOSING the valve clearance, causing a power loss as the valves may be slightly open all the time (eventually causing burnt valves), especially once the engine has heated up and heat expansion of the metals has closed the valve clearance even more.

 

Ihave a 450 forman s. I got the compression stroke up and adjusted my valves. They were lose and needed a slight adjustment. This is the fisrt time I did this. Does it sound like I did it right. 006 I need some comfirmation. Me and my house serve the Lord as well.thanks